Fresh sanctions have been levied against selected Russian companies and individuals as the United States accused them of assisting in global cyberattacks last year.

Five Russian companies and three individuals have been singled out in the sanctions, announced Monday, which the US says is in retaliation for assisting Russian military and intelligence services with “destabilizing cyber activities”.

“The United States is engaged in an ongoing effort to counter malicious actors working at the behest of the Russian Federation and its military and intelligence units to increase Russia’s offensive cyber capabilities. The entities designated today have directly contributed to improving Russia’s cyber and underwater capabilities through their work with the FSB (Federal Security Service) and therefore jeopardize the safety and security of the United States and our allies,” he said.

Earlier this year, both the US and UK governments publicly blamed Russia for the cyberattack last year that targeted Ukraine and spread around the world.

The ransomware attack, named NotPetya, infected the websites of Ukrainian organizations, including banks, ministries, newspapers and electricity firms. Similar infections were reported in France, Germany, Italy, Poland, Russia, the UK, the US and Australia, but 80 per cent of the breach was reported in Ukraine.

The cyberattack was based on a modified version of the Petya ransomware, hence the name NotPetya. Unlike the original ransomware, which demanded a Bitcoin payment to reverse infection, experts said this modified version was designed to spread quickly and encrypt all files on the infected computers. In some cases, the files were completely wiped in a way which prevented recovery.

Security researchers agreed soon after the attack that the main aim of NotPetya was to “exact maximum destruction and disruption, with Ukraine the clear target,” the Associated Press reported last year.

Russia denied responsibility for the attack, which was estimated to have cost companies around the world more than $1.2 billion.

Three people named in the sanctions, Aleksandr Tribun, Oleg Chirikov and Vladimir Kaganskiy, reportedly have ties to a company that allegedly specialises in hacking into undersea communications cables, the BBC reports.

The sanctions will prohibit the named companies and individuals from any transactions involving the US financial system.